The men's 110 metres hurdles event at the 2004 World Junior Championships in Athletics was held in Grosseto, Italy, at Stadio Olimpico Carlo Zecchini on 16, 17 and 18 July. 106.7 cm (3'6) (senior implement) hurdles were used.
| Gold | Aries Merritt | |
| Silver | Dayron Robles | |
| Bronze | Kevin Craddock |
18 July
Wind: -0.6 m/s
| Rank | Name | Nationality | Time | Notes | |||
|---|---|---|---|---|---|---|---|
| align=left | align=left | | 13.56 | ||||
| align=left | align=left | | 13.77 | ||||
| align=left | align=left | | 13.77 | ||||
| 4 | align=left | align=left |  | 13.96 | |||
| 5 | align=left | align=left |  | 14.10 | |||
| 6 | align=left | align=left | | 14.13 | |||
| 7 | align=left | align=left |  | 14.20 | |||
| 8 | align=left | align=left | 14.29 |
17 July
Wind: -0.3 m/s
| Rank | Name | Nationality | Time | Notes | |||
|---|---|---|---|---|---|---|---|
| 1 | align=left | align=left | | 13.65 | Q | ||
| 2 | align=left | align=left | | 13.74 | Q | ||
| 3 | align=left | align=left | | 13.98 | Q | ||
| 4 | align=left | align=left | | 14.03 | Q | ||
| 5 | align=left | align=left | 14.10 | ||||
| 6 | align=left | align=left |  | 14.12 | |||
| 7 | align=left | align=left |  | 14.41 | |||
| align=left | align=left | DQ | IAAF rule 162.7 |
Wind: -0.5 m/s
| Rank | Name | Nationality | Time | Notes | |||
|---|---|---|---|---|---|---|---|
| 1 | align=left | align=left | | 13.94 | Q | ||
| 2 | align=left | align=left | | 13.98 | Q | ||
| 3 | align=left | align=left | | 14.03 | Q | ||
| 4 | align=left | align=left | 14.18 | Q | |||
| 5 | align=left | align=left | 14.37 | ||||
| 6 | align=left | align=left |  | 14.39 | |||
| 7 | align=left | align=left |  | 14.57 | |||
| align=left | align=left | | DNF |
16 July
Wind: -0.1 m/s
| Rank | Name | Nationality | Time | Notes | |||
|---|---|---|---|---|---|---|---|
| 1 | align=left | align=left | | 14.07 | Q | ||
| 2 | align=left | align=left | | 14.11 | Q | ||
| 3 | align=left | align=left | | 14.18 | q | ||
| 4 | align=left | align=left | 14.22 | q | |||
| 5 | align=left | align=left |  | 14.46 | |||
| 6 | align=left | align=left |  | 14.73 | |||
| 7 | align=left | align=left | 14.99 | ||||
| 8 | align=left | align=left | | 15.05 |
Wind: +1.2 m/s
| Rank | Name | Nationality | Time | Notes | |||
|---|---|---|---|---|---|---|---|
| 1 | align=left | align=left | | 13.88 | Q | ||
| 2 | align=left | align=left | | 14.07 | Q | ||
| 3 | align=left | align=left | 14.10 | q | |||
| 4 | align=left | align=left | | 14.13 | q | ||
| 5 | align=left | align=left |  | 14.29 | |||
| 6 | align=left | align=left |  | 14.31 | |||
| 7 | align=left | align=left |  | 14.51 | |||
| 8 | align=left | align=left |  | 14.54 |
Wind: +1.8 m/s
| Rank | Name | Nationality | Time | Notes | |||
|---|---|---|---|---|---|---|---|
| 1 | align=left | align=left | | 13.82 | Q | ||
| 2 | align=left | align=left | | 13.99 | Q | ||
| 3 | align=left | align=left | | 14.17 | q | ||
| 4 | align=left | align=left | | 14.18 | q | ||
| 5 | align=left | align=left | | 14.31 | |||
| 6 | align=left | align=left | 14.67 | ||||
| 7 | align=left | align=left |  | 14.73 |
Wind: +1.8 m/s
| Rank | Name | Nationality | Time | Notes | |||
|---|---|---|---|---|---|---|---|
| 1 | align=left | align=left | | 13.83 | Q | ||
| 2 | align=left | align=left | 14.13 | Q | |||
| 3 | align=left | align=left |  | 14.27 | |||
| 4 | align=left | align=left | 14.41 | ||||
| 5 | align=left | align=left | 14.47 | ||||
| 6 | align=left | align=left |  | 14.68 | |||
| 7 | align=left | align=left | | 14.84 |
Wind: +1.3 m/s
| Rank | Name | Nationality | Time | Notes | |||
|---|---|---|---|---|---|---|---|
| 1 | align=left | align=left | | 13.82 | Q | ||
| 2 | align=left | align=left | 14.35 | Q | |||
| 3 | align=left | align=left | 14.49 | ||||
| 4 | align=left | align=left |  | 14.50 | |||
| 5 | align=left | align=left | 14.51 | ||||
| 6 | align=left | align=left | 14.52 | ||||
| 7 | align=left | align=left |  | 14.70 |
According to an unofficial count, 37 athletes from 28 countries participated in the event.